
The VentureFizz Podcast
Episode 446: Jack O'Brien - CEO & Co-Founder, Subconscious
Episode 446 of The VentureFizz Podcast features today’s guest is Jack O’Brien, Co-Founder & CEO of Subconscious. AI agents are rapidly transforming knowledge work, especially in sectors like software engineering, law, and finance. However, inference costs for AI agents present a massive challenge, as agentic workloads love chewing up tokens which in return ends up costing companies lots and lots of money. And context limits or rate limits are not the answer either. Subconscious was built to solve this exact challenge. Based on research out of MIT, Subconscious has built a specialized inference platform designed specifically for long-horizon AI agents. Using dynamic context compression and efficient caching, the platform allows developers and enterprises to run open-weight models faster, longer, and up to 80% cheaper. It reminds me of another company that was based on research out of MIT back in 1997: local tech giant Akamai, who helped speed up the internet based on distributed computing and intelligent routing. Subconscious recently announced $5.1 million in funding led by MassVentures, with participation from Foothill Ventures, Underscore VC, E14 Fund, Oakseed Ventures, and the Agent Fund. In this episode, we cover: * Jack’s background story, including being the nation’s top-ranked face-off specialist in lacrosse, his career in D1 lacrosse at Princeton, and his early entrepreneurial experience running Tiger Bed Rentals as a student through its acquisition. * His time as a software engineer at Google and what this experience taught him. * His serial startup journey, including building OnePager and its acquisition by Stonks. * The origin story of Subconscious and meeting his co-founder, Hongyin Luo. * How Subconscious’s inference runtime uses dynamic context compression to slash token costs while maintaining or even improving model performance. * Details on their newly announced $5.1M round of funding. * The rise of open source LLM’s versus closed frontier models. * His personal passions outside of work, including kite surfing. Podcast Sponsor: This podcast is brought to you by one of the strongest longtime supporters of the local startup ecosystem, Silicon Valley Bank, a division of First Citizens Bank. With more than 1,500 bankers and relationship advisors and $44B in loans as of Q4 2025 – SVB delivers expert guidance, specialized products and a team that knows the innovation economy inside and out. Learn more at SVB.com.





